A. Field of the Invention
The applicants' invention relates to a sleeper sofa using an air mattress instead of a conventional spring mattress and various assemblies and subassemblies of the sofa.
B. Background
More and more people are replacing their conventional, spring mattresses with air mattresses. Increased public acceptance of air mattresses is due, in part, to their superior sleeping comfort. Conventional air mattresses have a flexible body enclosing at least one air chamber that is inflatable using an air pump. Once inflated, the air chamber is made pressure-tight by closing a valve within a portal in the chamber. Such an inflated mattress typically has two opposed, planar surfaces, and the user sleeps on the top surface. To deflate the mattress, the user releases air from the chamber to collapse the mattress so that it may be folded for storage. Typically, the user may incrementally deflate the mattress to adjust the firmness of the mattress for comfort.
In contrast to a comfortable air mattress, the most reviled sleeping surface is a pull-out sleeper sofa, which is in widespread use. Commercially available sleeper sofas have a mattress folded within a sleeper sofa subassembly when the sleeper sofa is in the collapsed position. Although lacking in comfort, convertible sleeper sofa arrangements are popular because they provide a bed for overnight guests and, when not in use, fold out of the way to provide, normally with the aid of cushions, a seating surface. They do two jobs at once.
Conventional sleeper sofas are uncomfortable because of size constraints and the poor support provided by typical mattress support subassemblies. Because the mattress in a conventional sleeper sofa must fold into the sofa, it must be substantially thinner, and thus less comfortable, than a full-size bed mattress. The mattress may not be as well padded as a conventional bed mattress and the steel springs may not provide support as firm and even as a conventional bed mattress. This thin, unsupportive, lumpy sleeper sofa mattress is made even less comfortable by a flimsy and uneven support subassembly. Typical support subassemblies include a wire mesh slung across an open frame (or a spring-supported polymer weave called a trampoline) and hinge bars extending just below the wire mesh or trampoline. As most who have slept on a conventional sleeper sofa know, they are uncomfortable because the user feels a thin, lumpy flaccid mattress poorly supported on a wire mesh that is draped over several hinge bars and a metal mattress support structure, all of which are felt through the mattress.
Commercially available sleeper sofas cannot accommodate a full-thickness mattress, but they are nevertheless bulky and heavy because of the complex folding mattress frame. To extend the mattress frame from the sofa position to the open bed position often requires physical strength beyond some people's abilities because of advanced age or health infirmities. People who can fold and unfold the frame often pinch their fingers and skin their shins. Thus, a need exists in the art for an improved sleeper sofa that is at least as comfortable as a conventional bed and easy to extend and retract.